Hydraulic fluid pump and retainer assembly for same

ABSTRACT

A fluid end assembly of a hydraulic fluid pump includes a housing having a first housing bore and a second housing bore offset axially from the first housing bore. A plate is fastened to the housing. The plate has a first plate bore axially aligned with the first housing bore and a second plate bore axially aligned with the second housing bore. A first removable valve cover closes the first housing bore and a second removable valve cover closes the second housing bore. A first retainer engages the first plate bore and abuts the first removable valve cover and a second retainer engages the second plate bore and abuts the second removable valve cover.

CROSS REFERENCE TO RELATED APPLICATIONS

This application is a divisional of U.S. nonprovisional application Ser.No. 16/298,228, filed on Mar. 11, 2019 and entitled “HYDRAULIC FLUIDPUMP AND RETAINER ASSEMBLY FOR SAME.” The disclosure of the aboveapplication is incorporated herein by reference in its entirety.

FIELD OF THE INVENTION

The present invention relates to a hydraulic fluid pump and, moreparticularly, to a fluid end assembly of a hydraulic fluid pump.

SUMMARY

In one embodiment, the invention provides a fluid end assembly of ahydraulic fluid pump. The fluid end assembly includes a housing having afirst housing bore and a second housing bore offset axially from thefirst housing bore. A plate is fastened to the housing. The plate has afirst plate bore axially aligned with the first housing bore and asecond plate bore axially aligned with the second housing bore. A firstremovable valve cover closes the first housing bore and a secondremovable valve cover closes the second housing bore. A first retainerengages the first plate bore and abuts the first removable valve coverand a second retainer engages the second plate bore and abuts the secondremovable valve cover.

In another embodiment, the invention provides a method of assembling afirst valve cover and a second valve cover within a fluid end assemblyof a hydraulic fluid pump. The first removable valve cover is insertedinto a first housing bore of a housing of the fluid end assembly. Thesecond removable valve cover is inserted into a second housing bore ofthe housing of the fluid end assembly. A first plate bore of a plate isaxially aligned with the first housing bore. A second plate bore of theplate is axially aligned with the second housing bore. The plate isfastened to the housing of the fluid end assembly. A first retainer ispositioned into the first plate bore and into abutment with the firstremovable valve cover. A second retainer is positioned into the secondplate bore and into abutment with the second removable valve cover.

In yet another embodiment, the invention provides a hydraulic fluidpump. The hydraulic fluid pump includes a housing of a fluid end of thehydraulic fluid pump, the housing including a first axial end and asecond axial end opposite the first axial end, the housing having ahousing bore located at the first axial end. A plate is fastened to thehousing; the plate having a plate bore axially aligned with the housingbore. A removable valve cover closes the first housing bore. A retainerengages the plate bore and abuts the first removable valve cover. Eachfastener of a plurality of fasteners extends through the plate, thefirst axial end of the housing, and the second axial end of the housingto fasten the plate to the housing.

Other aspects of the invention will become apparent by consideration ofthe detailed description and accompanying drawings.

BRIEF DESCRIPTION OF THE DRAWINGS

FIG. 1 is a perspective view of a hydraulic fluid pump

FIG. 2 is a cross-sectional view of a fluid end assembly of a hydraulicfluid pump.

FIG. 3 is a perspective view of a retainer assembly of a hydraulic fluidpump.

FIG. 4 is a sectional view of the retainer assembly of FIG. 3 , shownthrough a retainer and a plurality of fasteners.

FIG. 5 is a cross-sectional perspective view of the retainer assembly ofFIG. 3 .

FIG. 6 is a perspective view of a retainer assembly of a hydraulic fluidpump according to another embodiment,

FIG. 7 is a sectional view of the retainer assembly of FIG. 6 , shownthrough a retainer and a plurality of fasteners.

FIG. 8 is a cross-sectional view of a retainer assembly of a hydraulicfluid pump, according to another embodiment.

DETAILED DESCRIPTION

Before any embodiments of the invention are explained in detail, it isto be understood that the invention is not limited in its application tothe details of construction and the arrangement of components set forthin the following description or illustrated in the following drawings.The invention is capable of other embodiments and of being practiced orof being carried out in various ways.

FIG. 1 illustrates a hydraulic fluid pump 10 of the type often usedduring drilling and hydraulic fracturing operations such as hydrocarbonor oil fracturing. The hydraulic fluid pump 10 includes a power end ordrive end or drive end assembly 12 that is largely enclosed within acasing 18. A fluid end or fluid end assembly 14 attaches to the driveend 12 and the casing 18 and includes at least one fluid end block 16. Adrive shaft 20 extends out of the casing 18 and provides for aconnection point for a prime mover such as a motor or engine. The primemover drives the drive shaft 20 at a desired speed to power the driveend 12. The drive end 12 typically includes a transmission (e.g., gears,belts, chains, etc.) that serve to step down the speed of the driveshaft 20 to a speed appropriate for the fluid end 14. The drive end 12includes a series of reciprocating mechanisms that in turn drives apiston or plunger (e.g., plunger 46 shown in FIG. 2 ) within arespective bore of the fluid end block 16 to pump a fluid.

The fluid end 14 is better illustrated in FIG. 2 . A housing 24 definesthe main body of the fluid end assembly 14 surrounding an interiorvolume 26. An inlet manifold 22 (FIG. 1 ) distributes fluid to an inletbore 30 of each fluid end block 16. An inlet valve 32 is positioned inthe inlet bore 30 to control flow from the inlet manifold 22 into theinterior volume 26 of the fluid end 14, and more specifically, theinterior volume 26 of the housing 24. An outlet bore 34 directspressurized fluid from the interior volume 26, past an outlet valve 38,and to an outlet manifold integrated into the fluid end 14 and having anoutlet 28 (FIG. 1 ) from the fluid end 14. The outlet manifold 28 is influid communication with the fluid end block 16 via the outlet bore 34and outlet valve 38. As shown, the inlet and outlet bores 30, 34 areaxially aligned with one another.

A plunger bore 40 extends perpendicular to the inlet and outlet bores30, 34 and supports a packing arrangement 42 and packing retainer 44.The reciprocating plunger 46 is movable within the plunger bore 40relative to the packing arrangement 42 and the packing retainer 44 topressurize fluid within the interior volume 26 and to the outletmanifold 28. A service bore 50 is formed in the housing 24 parallel withand axially aligned with the plunger bore 40 and provides access to theinterior volume 26 of the housing 24 without removal of the plunger 46,or the valves 32, 38. The service bore 50 may additionally provideaccess for insertion and removal of the plunger 46 and/or the inletvalve 32 from the remainder of the pump 10.

As shown, both the outlet bore 34 and the service bore 50 include valvecovers 52A, 52B and retainers 54. The valve covers 52A, 52B seal againstthe housing 24 to prevent fluid from the interior volume 26 from passingthrough the respective bores 34, 50. Each retainer 54 applies a force tothe respective valve cover 52A, 52B to hold the valve cover 52A, 52B ina sealing position against the housing 24. When the reciprocatingplunger 46 increases the pressure of the fluid within the interiorvolume 26 of the housing 24, a force is applied on the valve covers 52A,52B (either directly, as with the valve cover 52A of the service bore50, or indirectly, as with the valve cover 52B of the outlet bore 34).The retainer 54 applies a preload to the valve cover 52A, 52B tocounteract the force applied by the pressurized fluid and to preventunseating of the valve cover 52A, 52B from the housing 24.

FIGS. 3-5 illustrate an embodiment of the invention. Like elements areindicated by like reference numerals incremented by 100 (relative to thecomponents shown in FIGS. 1-2 ) and are similar to those elements exceptas otherwise described.

The retainer assemblies 158, 258 shown in FIGS. 3-7 are illustrated withrespect to the retainer 154A valve cover 152A. However, the retainerassemblies 158, 258 can be equally applied to the retainer 154B and thevalve cover 152B.

As shown in FIGS. 4-5 , the valve cover 152A is inserted into theservice bore 150 and includes a radial seal 160 positioned within achannel 160A in the valve cover 152A to provide a seal between the valvecover 152A and the housing 124. The valve cover 152A can additionally oralternatively be provided with an axial seal to engage the housing 124.The valve cover 152A is generally cylindrical with a diameter similar tothe diameter of the housing bore 150. The valve cover 152A furtherincludes a circumferential lip 162 for engaging a surface 156 of thehousing 124. As shown, the surface 156 is a first axial end 186 of thehousing 124. A second axial end 188 of the housing 124 is opposite thefirst axial end 186. The ends 186, 188 of the housing 124 are considered“axial” based on the orientation of the housing bore 150. The valvecover 152A is not threaded or otherwise fastened to the housing bore150, outside of a clearance fit and/or friction provided by the radialseal 160.

In contrast to the fluid end 14 shown in FIGS. 1-2 , the fluid end 114shown in FIGS. 3-5 includes a plate 136 abutting the first axial end 186of the housing 124 for supporting the retainers 154A. The plate 136 is aflat sheet of metal (e.g., steel, stainless steel, etc.) having athickness to support the retainer 154A. The plate 136 is formed separatefrom the housing 124 and attached to the housing 124 via fasteners 176.Forming the plate separate from the housing 124 decreases the overallsize of the housing 124 and the overall size of the raw materialnecessary to make the housing 124 in at least a width dimension.Alternatively or additionally, a plate may be fastened to the housing124 for supporting the retainers 154B, thereby limiting the overall sizeof the raw material necessary to make the housing 124 in the heightdimension as well.

With continued reference to FIGS. 3-5 , the plate 136 includes aplurality of plate bores 148, each plate bore 148 associated with andaligned with a housing bore 150 in the housing 124. As shown in FIG. 3 ,the housing 124 includes three housing bores 150. Each housing bore 150is an access bore for accessing an internal volume 126 associated with adifferent reciprocating plunger 146 and each housing bore 150 supports adifferent valve cover 152A. Each plate bore 148 is threaded (i.e., hasinternal threads 168) for engaging the external threads 170 of theretainer 154A.

As shown, the plate 136 is fastened to the housing 124 via fasteners176, and specifically via tie rods (or pad studs or stay rods) 180 andnuts 182, 184. Each tie rod 180 is an elongated cylindrical shaft thathas a length to extend through the first and second axial ends 186, 188of the housing 124. Each axial end 190, 192 of the tie rods 180 isthreaded (i.e., includes threads). As shown in FIGS. 3-5 , the firstaxial end 190 of the tie rods 180 is fastened to a nut 182 locatedadjacent the plate 136 such that the plate 136 is sandwiched between thenut 182 and the surface 156 of the housing 124. In some embodiments, aseal (not shown) may be sandwiched between the plate 136 and the housing124. As shown in FIG. 5 , the second axial end 192 of the tie rods 180may be fastened to a nut 184 similar to the first axial end 190, or, asshown, may otherwise terminate within a threaded aperture to preventaxial translation of the tie rod 180 relative to the housing 124. Eachtie rod 180 extends through an aperture 194 (e.g., unthreaded aperture)in the plate 136 and into and through an aperture 196 (e.g., anunthreaded aperture) in the housing 124.

With continued reference to FIG. 5 , the tie rods 180 extend to andthrough or into a portion of the drive end 112, or a component that isfastened to the drive end 112 such that the tie rods 180 (along with oneor more nuts 182, 184) fasten the drive end 112 to the fluid end 114.

Since the plate 136 is a single plate having a plurality of plate bores148, the plate bores 148 are accurately spaced relative to one anotherand can be quickly aligned with the housing bores 150 by aligning afirst one of the plate bores 148 relative to a first housing bore 150.Further, utilizing a single plate helps to provide a more consistentpreload across all valve covers 152A.

In operation, to assemble a plurality of valve covers 152A within afluid end assembly 114 of a hydraulic fluid pump 110, the fluid end 114is installed on the tie rods 180 by inserting the tie rods 180 throughthe unthreaded apertures 196. In some embodiments, the tie rods 180 maybe first installed relative to the drive end (similar to drive end 12)or to another component such that the tie rods 180 are positionedrelative to one another and the fluid end 114 is installed onto the tierods 180. In other embodiments, the tie rods 180 may be individuallyinserted into and through the apertures 196 and fastened at the secondend 192. With the fluid end 114 and tie rods 180 assembled, the plate136 is installed on the pad studs by axially aligning the apertures 194in the plate 136 with the tie rods 180. Once two of the apertures 194are aligned with two of the tie rods 180, the remainder of the apertures194 will be aligned with the remainder of the tie rods 180 and eachplate bore 148 will be axially aligned with the respective housing bore150. Once aligned, the plate 136 is axially translated along the lengthof the tie rods 180 and into abutment with the surface 156 of thehousing 124. In this way, the tie rods 180 function as guides foraxially aligning and translating the plate 136 relative to the housing124. The plate 136 is then fastened to the housing 124 of the fluid endassembly 112. Fastening the plate 136 to the housing 124 includessecuring the tie rods 180 at the first end 190 via a nut 182 andapplying a predefined torque to the nut 182. The plate 136 is therebysandwiched between the nuts 182 and the housing 124 to prevent movementof the plate 136 relative to the housing 124. The removable valve covers152A are inserted through respective plate bores 148 and into respectivehousing bores 150, where the radial seal 160 provides a seal between thevalve cover 152A and the housing 124. The retainers 154A are threadedinto respective plate bores 148 and are tightened (by threading theretainers 154A within the respective threaded plate bores 148) againstthe removable valve covers 152A. The retainers 154A may be inserted intothe plate 136 after the plate 136 is fastened to the housing 124. A usermay tighten the retainers 154A against the valve covers 152A to apply apredetermined preload on the valve covers 152A.

Alternatively, the removable valve covers 152A may be inserted into thehousing bores 150 prior to assembling the plate 136 to the housing 124,and the retainers 154A may be partially threaded into the plate 136prior to attaching the plate 136 to the housing 124; followed by finaladjustments such that the retainers 154A abut the valve covers 152A oncethe plate 136 is fastened to the housing 124.

In operation, to remove the valve covers 152A, the retainers 154A arerotated relative to the plate bore 148 until fully unthreaded. At thattime, the valve covers 152A can be accessed for removal or inspection.The plate 136 does not need to be removed to access or remove the valvecovers 152A. In other embodiments, the plate 136 may prevent axialremoval of the valve covers 152A, and need to be removed prior toremoval of the valve covers 152A. In such embodiments, the plate isremoved by unthreading the nuts 182 from the tie rods 180 and axiallymoving the plate 136 away from the surface 156 of the housing 124.

In some embodiments, the tie rods 180 may be used in combination withindividual plates (each plate having one plate bore and associated withone retainer 154A, one housing bore 150), where multiple plates arefastened to the housing 124.

FIGS. 6-7 illustrate another embodiment of the invention. Like elementsare indicated by like reference numerals incremented by 200 (relative tothe components shown in FIGS. 1-2 ) and are similar to those elementsexcept as otherwise described.

As shown in FIG. 6 , the plate 236 is modified relative to the plate 136shown in FIGS. 3-5 . The plate 236 is contoured such that the tie rods(similar to tie rods 180) do not extend through the plate 236, butrather extend around the plate 236 such that the tie rods do not fastenthe plate 236 to the housing 224. Rather, the plate 236 is fastened tothe housing via other threaded fasteners 278. As shown, the threadedfasteners 278 include threaded studs 266 and nuts 274. In otherembodiments, the threaded fasteners 278 may be embodied as, for example,bolts.

The studs 266 are threaded cylindrical posts having an axial length toextend through stud bores 298A in the plate 236 and into threaded studbores 298B in the housing 224. As shown, the stud bores 298A are spacedapart around a periphery of the plate 236. While the stud bores 298B arethreaded to engage the studs 266, the stud bores 298A in the plate maybe unthreaded. Each stud 266 protrudes out from the plate 236 such thata nut 274 can be threaded onto a distal end each stud 266. The threadsof the stud 266 permit linear translation of the nut 274 and the nut 274axially translates along the stud 266 via the threads to abut the plate236 and hold the plate relative to the housing 224. Alternatively, boltsmay be used to fasten the plate 236 to the housing 224.

The plate 236 includes a plurality of plate bores 248 that are alignedwith the housing bores 250 when the plate 236 is located adjacent thesurface 256 of the housing 224. Similarly, the stud bores 298A of theplate 236 are aligned with the threaded stud bores 298B of the housing224 when the plate bores 248 are aligned.

Similar to the embodiment shown above in FIGS. 3-5 , because the plate236 is a single plate having a plurality of plate bores 248, the platebores 248 are accurately spaced relative to one another and can bequickly aligned with the housing bores 250 by aligning a first one ofthe plate bores 248 relative to a first housing bore 250. Further,utilizing a single plate helps to provide a more consistent preloadacross all valve covers 252A.

In operation, to assemble a plurality of valve covers 252A within afluid end assembly 214 of a hydraulic fluid pump 210, some or all (i.e.,at least two) of the studs 266 are threaded into the stud bores 298B ofthe housing 224, thereby securing a second end of the studs 266 to thehousing 224. The operator aligns a first stud bore 298A of the plate 236over a first stud 266 already positioned in the first stud bore 298B. Asecond stud bore 298A of the plate 236 is similarly aligned with asecond stud 266 already positioned in the second stud bore 298B. Withtwo of the stud bores 298A axially aligned with their respective studbores 298B of the housing 224, any additional stud bores 298A are alsoaligned with their respective housing stud bores 298B. When the studbores 298A, 298B are aligned, the plate bores 248 are likewise alignedwith the housing bores 224. The plate 236 is fastened to the housing 224of the fluid end assembly 212. Once aligned, the plate 236 is axiallytranslated along the length of the studs 266 and into abutment with thesurface 256 of the housing 224. In this way, the studs 266 function asguides for axially aligning and translating the plate 236 relative tothe housing 224. Fastening the plate 236 to the housing 224 includesthreading the nut 274 onto a first end of each stud 266 and applying apredetermined torque to each nut 274. The plate 236 is therebysandwiched between the nuts 274 and the housing 224 to prevent movementof the plate 236 relative to the housing 224. The removable valve covers252A are inserted into respective housing bores 250 within the housing224 of the fluid end assembly 212. The retainers 254A are threaded intorespective plate bores 248 and are tightened (by threading the retainers254A within the respective threaded plate bores 248) against theremovable valve covers 252A. A user may tighten the retainers 254Aagainst the valve covers 252A to apply a predetermined preload on thevalve covers 252A.

The retainers 254A may be inserted into the plate 236 after the plate236 is fastened to the housing 224. Alternatively, the removable valvecovers 252A may be inserted into the housing bores 250 prior toassembling the plate 236 to the housing 224, and the retainers 254A maybe partially threaded into the plate 236 prior to attaching the plate236 to the housing 224; followed by final adjustments such that theretainers 254A abut the valve covers 252A once the plate 236 is fastenedto the housing 224. In some embodiments, bolts may be used in place ofthe studs 266 and the nuts 274.

In operation, to remove the valve covers 252A, the retainers 254A arerotated relative to the plate bore 248 until fully unthreaded. At thattime, the valve covers 252A can be accessed for removal or inspection.In some embodiments, the plate 236 does not need to be removed to accessor remove the valve covers 252A. In other embodiments, the plate 236 mayprevent axial removal of the valve covers 252A, and need to be removedprior to removal of the valve covers 252A. In such embodiments, theplate is removed by unthreading the nuts 274 from the studs 266 andaxially moving the plate 236 away from the surface 256 of the housing224.

FIG. 8 illustrates another embodiment of the invention. Like elementsare indicated by like reference numerals incremented by 300 (relative tothe components shown in FIGS. 1-2 ) and are similar to those elementsexcept as otherwise described.

As shown in FIG. 8 , the plate 336 is similar to the plate 236 shown inFIGS. 6-7 , though the location of the plate 336 is dissimilar, as theplate 336 is positioned at the outlet bore 334 rather than the servicebore 350. Therefore, the plate 336 is positioned over the valve cover352B rather than the valve cover 352A of the service bore 350.

The plate 336 is fastened to the housing via threaded fasteners 378. Asshown, the threaded fasteners 378 are embodied as bolts. In otherembodiments, the threaded fasteners 378 may include, for example,threaded studs and nuts. The fasteners 378 are threaded cylindricalposts having a head and an axial length to extend through stud bores398A in the plate 336 and into threaded stud bores 398B in the housing324. Similar to the embodiments shown in FIGS. 3 and 6 , the stud bores398A are spaced apart around a periphery of the plate 336. While thestud bores 398B are threaded to engage the studs 378, the stud bores398A in the plate may be unthreaded.

The plate 336 includes a plurality of plate bores 348 (extending intothe page, as shown in FIG. 8 ) that are aligned with the housing bores334 when the plate 336 is located adjacent the surface 356 of thehousing 324. Similarly, the stud bores 398A of the plate 336 are alignedwith the threaded stud bores 398B of the housing 324 when the platebores 348 are aligned. Because the plate 336 is a single plate having aplurality of plate bores 348, the plate bores 348 are accurately spacedrelative to one another and can be quickly aligned with the housingbores 334 by aligning a first one of the plate bores 348 relative to afirst housing bore 334. Further, utilizing a single plate helps toprovide a more consistent preload across all valve covers 352B.

In operation, to assemble a plurality of valve covers 352B within afluid end assembly 314 of a hydraulic fluid pump, the valve 338 andvalve cover 352B are positioned within the housing bore 324. If thefasteners 378 are studs or other fasteners capable of extending fullythrough the stud bores 398B in the plate 336, some or all (i.e., atleast two) of the fasteners 378 are threaded into the stud bores 398B ofthe housing 324, such that the plate 336 can be aligned to the housingby extending over the fasteners 378, as described with respect to FIGS.3-7 above. If the fasteners 378 are bolts that extend through the plate336 and terminate within the housing 324, the plate 336 is otherwisealigned with the openings prior to insertion of the fasteners 378.Fastening the plate 336 to the housing 324 includes threading a nut ontothe fastener 378 or tightening the fastener 378 against the plate 336.The plate 336 is thereby sandwiched against the housing 324 to preventmovement of the plate 336 relative to the housing 324. The removablevalve covers 352B are inserted into respective housing bores 334 withinthe housing 324 of the fluid end assembly. The retainers 354B arethreaded into respective plate bores 348 and are tightened (by threadingthe retainers 354B within the respective threaded plate bores 348)against the removable valve covers 352B. A user may tighten theretainers 354B against the valve covers 352B to apply a predeterminedpreload on the valve covers 352B.

The retainers 354B may be inserted into the plate 336 after the plate336 is fastened to the housing 324. Alternatively, the removable valvecovers 352B may be inserted into the housing bores 334 prior toassembling the plate 336 to the housing 324, and the retainers 354B maybe partially threaded into the plate 336 prior to attaching the plate336 to the housing 324; followed by final adjustments such that theretainers 354B abut the valve covers 352B once the plate 336 is fastenedto the housing 324.

In operation, to remove the valve covers 352B, the retainers 354B arerotated relative to the plate bore 348 until fully unthreaded. At thattime, the valve covers 352B can be accessed for removal or inspection.In some embodiments, the plate 336 does not need to be removed to accessor remove the valve covers 352B. In other embodiments, the plate 336 mayprevent axial removal of the valve covers 352B, and need to be removedprior to removal of the valve covers 352B. In such embodiments, theplate is removed by unthreading the fasteners 378 and moving the plate336 away from the surface 356 of the housing 324.

Various features and advantages of the invention are set forth in thefollowing claims.

What is claimed is:
 1. A method of assembling a first removable valvecover and a second removable valve cover within a fluid end assembly ofa hydraulic fluid pump, the method comprising: inserting the firstremovable valve cover into a first housing bore of a housing of thefluid end assembly; inserting the second removable valve cover into asecond housing bore of the housing of the fluid end assembly; axiallyaligning a first plate bore of a plate with the first housing bore;axially aligning the second plate bore of the plate with the secondhousing bore; fastening the plate to the housing of the fluid endassembly; positioning a first retainer into the first plate bore andinto abutment with the first removable valve cover; and positioning asecond retainer into the second plate bore and into abutment with thesecond removable valve cover.
 2. The method of claim 1, whereinfastening the plate to the housing includes abutting the plate against asurface of the housing, wherein inserting the first removable valvecover into the first housing bore includes abutting a circumferentiallip of the first removable valve cover against the surface of thehousing, and wherein inserting the second removable valve cover into thesecond housing bore includes abutting a circumferential lip of thesecond removable valve cover against the surface of the housing.
 3. Themethod of claim 1, wherein fastening the plate to the housing of thefluid end assembly includes extending a plurality of fasteners throughthe plate and into the housing.
 4. The method of claim 1, whereinfastening the plate to the housing of the fluid end assembly includesextending a plurality of fasteners through the plate, into a first axialend of the housing, and through a second axial end of the housing,opposite the first axial end.
 5. The method of claim 1, whereinpositioning the first retainer into the first plate bore includesthreading the first retainer into the first plate bore, and whereinpositioning the second retainer into the second plate bore includesthreading the second retainer into the second plate bore.
 6. The methodof claim 1, wherein fastening the plate to the housing includesinserting a rod through the plate and into the housing, and threading anut onto the rod and into axial abutment with the plate.
 7. The methodof claim 1, wherein the first removable valve cover is disposed betweenthe first retainer and the first housing bore, and wherein the secondremovable valve cover is disposed between the second retainer and thesecond housing bore.
 8. A method of assembling a removable valve coverwithin a fluid end assembly of a hydraulic fluid pump, the methodcomprising: inserting the removable valve cover into a housing bore of ahousing of the fluid end assembly; axially aligning a plate bore of aplate with the housing bore; fastening the plate to the housing of thefluid end assembly; and positioning a retainer into the plate bore andinto abutment with the removable valve cover.
 9. The method of claim 8,wherein fastening the plate to the housing includes abutting the plateagainst a surface of the housing, and wherein inserting the removablevalve cover into the housing bore includes abutting a circumferentiallip of the removable valve cover against the surface of the housing. 10.The method of claim 8, wherein fastening the plate to the housing of thefluid end assembly includes extending a plurality of fasteners throughthe plate and into the housing.
 11. The method of claim 8, whereinfastening the plate to the housing of the fluid end assembly includesextending a plurality of fasteners through the plate, into a first axialend of the housing, and through a second axial end of the housing,opposite the first axial end.
 12. The method of claim 8, whereinpositioning the retainer into the plate bore includes threading theretainer into the plate bore.
 13. The method of claim 8, whereinfastening the plate to the housing includes inserting a rod through theplate and into the housing, and threading a nut onto the rod and intoaxial abutment with the plate.
 14. The method of claim 8, wherein theremovable valve cover is disposed between the retainer and the housingbore.
 15. A method of assembling a removable valve cover within a fluidend assembly of a hydraulic fluid pump, the method comprising: axiallyaligning a plate bore of a plate with a housing bore of a housing of thefluid end assembly; fastening the plate to the housing of the fluid endassembly; inserting the removable valve cover through the plate bore andinto the housing bore; and positioning a retainer into the plate boreand into abutment with the removable valve cover.
 16. The method ofclaim 15, wherein fastening the plate to the housing includes abuttingthe plate against a surface of the housing, and wherein inserting theremovable valve cover into the housing bore includes abutting acircumferential lip of the removable valve cover against the surface ofthe housing.
 17. The method of claim 15, wherein fastening the plate tothe housing of the fluid end assembly includes extending a plurality offasteners through the plate and into the housing.
 18. The method ofclaim 15, wherein fastening the plate to the housing of the fluid endassembly includes extending a plurality of fasteners through the plate,into a first axial end of the housing, and through a second axial end ofthe housing, opposite the first axial end.
 19. The method of claim 15,wherein positioning the retainer into the plate bore includes threadingthe retainer into the plate bore.
 20. The method of claim 15, whereinfastening the plate to the housing includes inserting a rod through theplate and into the housing, and threading a nut onto the rod and intoaxial abutment with the plate.